This command displays a numbered list of the calling stack
frames including the function names and source line numbers. You
set backtrace to control the default
call stack display settings.
Each frame is assigned a number that increases from the bottom frame (zero) through the call stack to the top frame that is the start of the application.
nframes from the bottom of the call stack.
nframes from the top of the call stack.
Specifies the additional display of local variables.